1. Statement of the Technical Field
The present invention relates to the field of visually graphing multi-range data sets and more particularly to the visual adjustment of a graph of multi-range data sets.
2. Description of the Related Art
Multi-range data sets can be defined as the collection of two or more sets of data, each data set having a range of values which differs from the range of values of others of the sets of data. Typically, data sets having disparate value ranges are grouped together in a multi-range data set in attempt to correlate the values of each data set, notwithstanding the disparate range of values of each data set. Thus, an example of a multi-range data can include a set of changing temperatures in a room over time and a count of the number of people in the room over the same time period. While the set of changing temperatures might have a range of seventy degrees Fahrenheit to eighty-degrees Fahrenheit, the count of people might have a range of zero to ten.
In order to correlate different data sets in a multi-range data set, it can be helpful to overlay within a single graph, individual graphs produced for each set of data in the multi-range data set. In this way, the effect of common changes in one component of the multi-range data set can be evaluated across multiple sets of data. For instance, by overlaying individual graphs for the number of patent applications filed per month and the unemployment rate per month over a fixed period of time, a correlation may be ascertained between changes in the number of patent applications filed and changes in the unemployment rate. Still, as the range of values for the unemployment rate can vary from zero to one-hundred, the range of values for patent application filings can range in the thousands. Hence, the scaling down of the range of values for patent application filings, or alternatively the scaling upwards of the range of values for the unemployment rate, will be required.
Scaling multi-range data sets in a single graph can be problematic, however, where the resolution required to qualitatively depict value changes for one set of data in the multi-range data set significantly vary from the resolution required to qualitatively depict value changes for other sets of data in the multi-range data set. For example, in the case of a multi-range data set consisting of one set of data directed to the computational throughput (number of operations per second) of a microprocessor at a given clock frequency, and a second set of data directed to the temperature of the microprocessor at a given clock frequency, changes in temperature responsive to changes in clock frequency will not be readily apparent given the scale of the graph required to accurately illustrate changes in computational throughput relative to changes in clock frequency. Thus, the concurrent display of a multi-range data set can prove less than helpful where the value range of individual sets of data in the multi-range data set vary widely.
In U.S. Pat. No. 5,261,031 to Saito for METHOD AND APPARATUS FOR ENLARGING A TREND GRAPH, it was recognized that in a conventional trend graph representation, where scaling occurs so as to enlarge or expand a portion of the graph, it can be impossible to compare the displayed enlarged portion with other undisplayed enlarged portions of the overall acquired data. In response, Saito proposed the subdivision of the graph display screen into a middle enlarged portion and upper and lower reduced portions. Accordingly, an entire set of data can be represented graphically in the Saito invention, merely by displaying compressed exterior sections of the graph in the upper and lower portions of the display screen while enlarging that section of the graph in the middle enlarged portion of the display screen in which substantial resolution will be required.
Notwithstanding the Saito solution, it will be apparent to one skilled in the art that the Saito invention is limited strictly to a trifurcation of the display screen. Specifically, in Saito, only a single middle section of the graph can be enlarged, while the exterior sections of the graph must be compressed. Secondly, as the display screen is limited to a single enlarged section, multiple sections of the graph cannot be enlarged selectively and simultaneously. Thus, at present a need remains for an effective means for proportionally adjusting a graph of multi-range data sets.